1. Field of the Invention
The present invention relates generally to an electron beam welding apparatus. More specifically, the invention relates to an electron beam welding apparatus which is free from welding spatter adhering to or sticking on the peripheral walls of the apparatus. The present invention also relates to a method for easily removing welding spatter in the apparatus.
2. Description of the Background Art
Electron beam welding technology is a modern welding technology which has a much higher welding efficiency in comparison with conventional welding processes, such as arc welding. As is well known, the electron beam used in electron beam welding is a higher energy than the arc beam used in arc welding. Electron beam welding apparatuses have been disclosed in Japanese Patent First (unexamined) Publications (Tokkai) Showa 62-238084, published on Oct. 19, 1987 and 63-149089, published on June 21, 1988, and Japanese Utility Model First (unexamined) Publication (Jikkai) Showa 63-116192, published on July 27, 1988.
In the conventional electron beam welding apparatuses problems are encountered. For example, the electron beam welding may generate spatter distributed outside of the work area. The welding spatter then adheres to or accumulates on the inner periphery of an enclosed apparatus housing. Since such welding spatter blocks on the inner periphery may contain air, the air carried with the blocks of the welding spatter may require prolonged periods of time for establishing the required degree of vacuum to successfully perform the electron beam welding, thereby lowering the efficiency of the electron beam welding operation.
Furthermore, since the welding spatter may be firmly adhered to or stuck on the periphery of the apparatus, the operation for removing the stuck spatter becomes difficult and require a relative long period of time.